Base expression node types on `dataclasses` #669

Job	Run time
Pylint	51s
Mypy	24s
Documentation	37s
Tests for downstream project loopy	3m 38s
Pytest on Py3.8	29s
Ruff	5s
Tests for downstream project pytential	10m 28s
Pytest on Py3.9	34s
Pytest on Py3.x	34s
Tests for downstream project pytato	6m 21s
	24m 1s

Provide feedback